In order to load and unload manifest items from a boat it is customary to provide a gangplank for passengers and small cargo items. Changing water levels give rise to the need to provide adjustable loading and unloading ramps. Ramps are not only necessary for ocean going boats but are also needed for loading and unloading manifest items of barges. Changes in river water levels present problems similar to changing tides. Although a flat ramp may be satisfactory for loading and unloading operations if the slope of the ramp is not steep, the changing tides and river levels give rise to a need for a safer conveyance surface with steps being generally preferred. In providing a pier mounted access ramp to a barge there is a need to maintain the same orientation of the barge boarding platform regardless of the slewed condition of the ramp. In other words it is desirable for the exit from the barge boarding platform to face the same direction relative to the barge regardless of the slewed position of the ramp.